Abstract: The composition of local ecological communities is thought to be driven by a combination of niche- and dispersal-driven processes. Data collected with Baited Remote Underwater Stereo-Video systems (stereo-BRUVs) from reefs within the Agulhas Bioregion were used to investigate the structure of resident sparid (Sparidae) reef fish communities. The results relate spatial turnover in community structure (β-diversity) to variation in spatial connectivity and the abiotic environment, and integrate body length variation at both the intraspecific and interspecific level to test alternative theories of species coexistence.